Figure 4. Viabilities of cells after ultrasound (US)-induced cytosolic delivery of saporin (Sap). DLD1 cells were treated with the nano-droplets (PCNDs) with or without Sap and then were exposed to ultrasound (US) or not. In the same way, the viability of intact cells was examined. The viability was normalized to that of the intact cells. Each bar represents the mean ± S.E. (n = 3). *p < 0.01 and **p < 0.05 versus the cells treated with both PCNDs carrying Sap and US (t-test).